V. appendix – Measurement Computing Personal488 rev.3.0 For DOS & Windows 3.Xi User Manual
Page 385
ASCII Character Codes & IEEE 488 Bus Line Messages
V. APPENDIX
V-370
Personal488 User’s Manual, Rev. 3.0
V. APPENDIX
Bus States, Bus Lines & Bus Commands
Bus State
Bus Lines
Data Transfer (DIO) Lines
8
7
6
5
4
3
2
1
Hex Value (QuickBASIC)
&H80
&H40
&H20
&H10
&H08
&H04
&H02
&H01
Decimal Value
128
64
32
16
8
4
2
1
Bus Management Lines
IFC
Interface Clear
REN
Remote Enable
IEEE 488 Interface: Bus Management Lines
ATN
Attention (&H04)
0
0
0
0
0
1
0
0
EOI
End-Or-Identify (&H80)
1
0
0
0
0
0
0
0
SRQ
Service Request (&H40)
0
1
0
0
0
0
0
0
IEEE 488 Interface: Handshake Lines
DAV
Data Valid (&H08)
0
0
0
0
1
0
0
0
NDAC
Not Data Accepted (&H10)
0
0
0
1
0
0
0
0
NRFD
Not Ready For Data (&H20)
0
0
1
0
0
0
0
0
Serial Interface: Bus Management Lines
DTR
Data Terminal Ready (&H02)
0
0
0
0
0
0
1
0
RI
Ring Indicator (&H10)
0
0
0
1
0
0
0
0
RTS
Request To Send (&H01)
0
0
0
0
0
0
0
1
Serial Interface: Handshake Lines
CTS
Clear To Send (&H04)
0
0
0
0
0
1
0
0
DCD
Data Carrier Detect (&H08)
0
0
0
0
1
0
0
0
DSR
Data Set Ready (&H20)
0
0
1
0
0
0
0
0
Bus State
Bus Commands
Data Transfer (DIO) Lines
(IEEE 488)
(ATN is asserted “1”)
8
7
6
5
4
3
2
1
Hex Value (QuickBASIC)
&H80
&H40
&H20
&H10
&H08
&H04
&H02
&H01
Decimal Value
128
64
32
16
8
4
2
1
DCL
Device Clear
x
0
0
1
0
1
0
0
GET
Group Execute Trigger (&H08)
x
0
0
0
1
0
0
0
GTL
Go To Local (&H01)
x
0
0
0
0
0
0
1
LAG
Listen Address Group (&H20-3F)
x
0
1
a
d
d
r
n
LLO
Local Lock Out (&H11)
x
0
0
1
0
0
0
1
MLA
My Listen Address
x
0
1
a
d
d
r
n
MTA
My Talk Address
x
1
0
a
d
d
r
n
PPC
Parallel Poll Config
x
1
1
0
S
P2
P1
P0
PPD
Parallel Poll Disable (&H07)
x
0
0
0
0
1
1
1
PPU
Parallel Poll Unconfig (&H15)
x
0
0
1
0
1
0
1
SCG
Second. Cmd. Group (&H60-7F)
x
1
1
c
o
m
m
d
SDC
Selected Device Clear (&H04)
x
0
0
0
0
1
0
0
SPD
Serial Poll Disable (&H19)
x
0
0
1
1
0
0
1
SPE
Serial Poll Enable (&H18)
x
0
0
1
1
0
0
0
TAG
Talker Address Group (&H40-5F)
x
1
0
a
d
d
r
n
TCT
Take Control (&H09)
x
0
0
0
1
0
0
1
UNL
Unlisten (&H3F)
x
0
1
1
1
1
1
1
UNT
Untalk (&H5F)
x
1
0
1
1
1
1
1
(x = “don’t care”)